Just saw [this tweet][1] coming from [a post on reddit][2].

Apparently if you hold down the trigger button while shocking someone it will kill them.

Haven't tested yet...


  [1]: https://twitter.com/#!/Demize99/status/143708825009139712
  [2]: http://www.reddit.com/r/battlefield3/comments/n53u6/why_cant_you_kill_with_the_defibrillator/